Conventionally, an ESC (Electronic Stability Control) system is known (for example, see Published Japanese translation No. 2004-506572 of a PCT international application) which executes a control for stabilizing a vehicle based on detection signals from a vehicular motion quantity sensor and a steering sensor, wherein vehicular motion quantity sensor includes a driving dynamics sensor, such as a yaw rate sensor and a lateral acceleration sensor. In this ESC system, the vehicular motion quantity sensor is located in an engine room of the vehicle, while the steering angle sensor is located at a place which is in the vicinity of a rotation axis of a steering and is in a passenger's compartment of the vehicle. In addition, the vehicular motion quantity sensor and a controller (ECU) of the ESC system are put together, and the steering angle sensor is connected with the ECU of the ESC system through electrical wiring harnesses. Thus, a detection signal from each sensor is inputted to the controller.
However, since the vehicular motion quantity sensor and the steering angle sensor are located separately, in the conventional way, wirings for connecting the vehicular motion quantity sensor with the ECU are installed to a place which is significantly different from a place to which wirings for connecting the steering angle sensor with the ECU are installed. In the case that the vehicular motion quantity sensor and the steering angle sensor are installed to different places, a structure for installation is required for each of the sensors. In addition, it is not easy to install the sensors since the sensors have to be installed individually. Because the wirings become intricate in their configuration and it becomes not easy to install the sensors, it takes a high cost to obtain the sensor device.